1. Field of the Invention
The present invention relates to a concrete retaining wall and a method for constructing the same. More particularly, the present invention relates to a green concrete retaining wall in which flora, such as plants, grasses, flowers and the like, can be cultured, and a method for constructing the same. The term xe2x80x9cgreen concrete retaining wallxe2x80x9d used herein means the concrete retaining wall in which various kinds of plants can be implanted, seeded, cultured and/or grown.
2. Description of the Prior Art
On the whole, when a steep slope is artificially built up by cutting or banking a naturally sloping land, a concrete structure is used. There are known to the prior art vertical and trapezoidal (FIG. 1b), watertight, concrete retaining wall structures for use in the construction of a steep slope.
Most of the studies that have been done for concrete retaining walls relate to use of concrete forms in constructing reinforced concrete retaining walls from steel and watertight concrete and to prefabrication of blocks which can be formed into concrete retaining walls simply by assemblage without using concrete forms.
For instance, Korean Pat. No. 238494 discloses a retaining wall construction method using concrete blocks, in which reinforcing bars are arranged crossways to provide structural stability, thereby constructing concrete retaining walls at heights from less than 2.0 m to 10.0 m without using concrete forms. According to this method, the arrangement structure and quantity of reinforcing bars can be suitably selected depending on construction situations, including the height of the retaining wall and the soil pressure, so that there can be brought about an economic benefit. In addition, this method enjoys the advantage of freely constructing curved sides.
Also, there are disclosed prefabricated concrete retaining walls (Korean Pat. Publication No. 74-987), concrete blocks for use in retaining walls (Korean Pat. No. 16123), and flexible joints for concrete retaining walls (Korean Pat. No. 128,126).
In an aspect of mechanical (structural) analysis, typically, concrete retaining walls are constructed with watertight reinforced concrete for resisting the overturning and the sliding failure and securing desired the bearing capacity force, and with steel bars for accomplishing desired mechanical and structural resistance to bending stress, shearing stress, or etc. Also, the overturning, the sliding failure, and the bearing capacity failure are the subjects of which account is taken in designing the appearance and dimension of concrete retaining walls.
However, most of conventional concrete retaining wall structures stand, taking straight shapes, such as vertical planes, with boring gray colors, and defiling the appearance of the street. Also, conventional concrete retaining wall structures require a long period of time for their construction. Because of taking vertical planes, conventional concrete retaining walls are under a high active earth pressure and are provided with long low plates (the base slab) to withstand the high active earth pressure. Further, to cope with the high active earth pressure, not only does the concrete retaining wall have a large cross section which is responsible for resistance to bending, but the earth work is required to have the soil at the back side of the wall cut in a large amount. With such structures, conventional retaining walls are likely to suffer the sliding failure and the overturning when water is not properly drained. Accordingly, in consideration of bending resistance and shear resistance against active earth pressure, reinforcing bars must be arranged in the watertight concrete of the retaining walls. However, design drawings for showing the arrangement of reinforcing bars are complicated and difficult to make. Additionally, when following the instruction of the design drawings, undesirable structures may be constructed as a result of miswriting, misreading or other supervisory mistakes. During the application of concrete to the work site, material segregation takes place, giving difficulty to the quality control. Difficulty is also found in the application of reinforcing bars to concrete retaining walls. Further, conventional concrete retaining walls suffer from the disadvantage in that it is difficult to accurately predict what will happen if concrete forms are deformed during the application of concrete. Joints, which are sometimes formed to link parts of conventional concrete retaining walls to each other therethrough, have negative influence on the appearance of the concrete retaining walls. During the curing of the concrete applied for the construction of retaining walls, cracks may be formed, deteriorating the endurance of the retaining walls constructed. Moreover, conventional concrete retaining walls are likely to suffer structural deformation as well as cracking, and there are no methods for perfectly compensating for either of them. Conventional concrete retaining walls are limited to 9.0 m in construction height.
Therefore, there remains a need for a concrete retaining wall structure which is structurally safe and can be constructed within a short period of time and in which flora, such as plants, lawns, flowers, etc., can be implanted and grown.
Leading to the present invention, the intensive research on concrete retaining walls, conducted by the present inventors, resulted in the finding that a steel skeleton in which aerial H beams stand at a certain angle to basal H beams can resist the overturning and the sliding failure and secure desired the bearing capacity force and, that artificial greening soil, if applied to retaining wall, allows plants to be cultured, contributing to the attractive appearance of the street.
Therefore, it is an object of the present invention to provide a concrete retaining wall which is structurally solid and can be constructed within a short period of time.
It is another object of the present invention to provide a concrete retaining wall in which plants, grasses, flowers and the like can be implanted and grown.
It is a further object of the present invention to provide a method for constructing such a concrete retaining wall.
In an aspect of the present invention, there is provided a method for constructing a concrete retaining wall structure, comprising the steps of: establishing a steel skeleton comprising basal H beams, aerial H beams, L beams, structural steel tubes and steel plates, said basal H beams and said aerial beams being arranged in a direction parallel with the earth surface and at a significant angle to the earth surface, respectively, at such space intervals and dimensions that the retaining wall structure has sufficient bending resistance to overcome the active earth pressures, said L beams, said structural steel tubes and said steel plates being provided as reinforcements between said arranged H beams; applying watertight concrete to the H beams formed as bases of the steel skeleton in the horizontal direction to support the steel skeleton; providing wire meshes onto the vertically directing H beams, the L beams, the structural tubes and steel plates; coating the wire mesh-mounted structure with water-permeable concrete to form a stepped or embossed external surface; and covering the concrete with artificial greening soil, the artificial greening soil allowing the growth of flora therein.